British Pat. No. 989,052 discloses an apparatus for attaching a fabric strap to D-shaped metal rings in which the strap is folded longitudinally just before being inserted up through the horizontally disposed rings. After such insertion the rings are slid horizontally to fold the leading end of the strap back over the trailing portion, and then the extreme trailing end of the strap is folded up over the leading end and the three superimposed layers of the strap are sewed to each other.
U.S. Pat. Nos. 3,785,907 and 3,898,119 disclose an apparatus and method for assembling a fabric seat belt to an apertured anchor plate in which the strap is folded longitudinally before being inserted perpendicularly through the anchor plate. Following this, the leading end of the belt is folded over and secured to a trailing portion of the belt at the opposite side of the anchor plate.